There is known a technology providing assistance for a driver in driving a vehicle based on information extracted from an image which has been formed by an imaging apparatus provided on the vehicle, for example.
A specific example of this driving assistance technology for assisting a driver is emission of a warning at the time of deviation of the vehicle of the driver from a lane based on recognition of a white line on a roadway contained in an image. Another example is emission of an alert for collision prevention based on recognition of another vehicle or person present before or behind the vehicle of the driver in an image.
Accordingly, an image around the vehicle formed by the imaging apparatus offers information useful for driving assistance. For realizing extraction of such useful information with more certainty, formation of a clear image containing a subject to notice is essential.
As an example of a technology associated with the imaging apparatus, there has been currently proposed a technology which arranges a cover glass provided on a front surface of an imaging device such that a light entrance surface of the cover glass is located obliquely to the imaging device to reduce interference of light reflected inside the cover glass (for example, see Patent Document 1).
There has been further proposed a technology associated with the imaging apparatus of a type containing a light source for illuminating a subject. According to this technology, a camera cover is obliquely fixed to prevent entrance of light into an imaging surface of the imaging apparatus after the light is emitted from the light source and reflected on the camera cover (for example, see Patent Document 2).